public class Exercise1 {
    public static void main(String[] args) {
        // 1. 基本运算
        int a = 15, b = 4;
        System.out.println("和: " + (a + b));
        System.out.println("差: " + (a - b));
        System.out.println("积: " + (a * b));
        System.out.println("商: " + (a / b));
        
        // 2. 判断偶数
        int num = 10;
        if (num % 2 == 0) {
            System.out.println(num + " 是偶数");
        } else {
            System.out.println(num + " 是奇数");
        }
        
        // 3. 温度转换
        double celsius = 25.0;
        double fahrenheit = celsius * 9/5 + 32;
        System.out.println(celsius + "°C = " + fahrenheit + "°F");
    }
}
